1. Field of the Invention
The invention relates to brushes and methods for collecting sample tissue from an endometrial cavity to aid diagnosing of endometrial cancer.
2. Description of the Prior Art
For a number of years, the incidence of cervical cancer was greater than the incidence of endometrial cancer. In order to diagnose cervical cancer a reliable, inexpensive treatment, the well-known Pap test, is widely utilized to diagnose cervical cancer. The Pap test is widely accepted by physicians and patients because of its reliability, low cost, convenience of application, and painlessness. Patients are not hesitant to periodically submit to the Pap test. Consequently, cervical cancer is usually diagnosed sufficiently early to be effectively treated. As a result of such effective treatment, the incidence of cervical cancer has become smaller than the incidence of endometrial cancer. This has occurred because until now, reliable, convenient, inexpensive, relatively painless methods and devices for obtaining samples of endometrial tissue and cells have not been available.
One known collecting device for endometrial cell and tissue samples, called a Medoza Canula, includes a curved plastic stem to facilitate its insertion into an endometrial cavity and a head having annular plastic flanges which operate to scrape cells from the walls of the endometrial cavity. The Medoza Canula includes a retractable protective sleeve to cover the head and the plastic flanges thereof to prevent wetting and contamination during insertion of the device through the patient's cervix. Once the head of the Medoza Canula is properly positioned in the endometrial cavity, the protective sleeve is retracted, exposing the plastic flanges. The handle is then manipulated forward and backward to cause the plastic flanges to scrape cells and tissue from the walls of the endometrial cavity. However, the Medoza Canula has a fixed depth limiting member which limits the depth of penetration of the head into the endometrial cavity. Consequently, for some patients the plastic flanges do not reach sufficiently deeply into the endometrial cavity to collect sample cells or tissue for analysis. Another disadvantage of the Medoza Canula is that the plastic flanges do not scrape the walls of the endometrial cavity sufficiently effectively to collect all of the cells and tissue which should be analyzed for presence of cancerous cells. The plastic flanges do not effectively scrape loose tissue and cells in response to rotation of the handle. Further, the plastic flanges "pick up" loose cells, but do not effectively scrape or pick up cells or tissue which is very deep within the endometrial walls. This prevents analysis of a suitably broad spectrum of potentially cancerous cells which might be present in the tissue of the endometrial walls. Further, the adherance of scraped cells to the plastic flanges of the Medoza Canula is thought to be inadequate to ensure retention of such cells on the flanges during withdrawal of the head through the cervix. Finally, the plastic flanges of the Medoza Canula do not efficiently collect sample tissue and cells from the deepest portions of the endometrial cavity. This is a serious shortcoming, because endometrial cancer frequently begins its growth in the deepest portions of the endometrial cavity.
Another known collecting device for endometrial cell and tissue samples is disposed in U.S. Pat. No. 3,945,372, by Milan et al, issued Mar. 23, 1976. The endometrial tissue obtaining instrument described in the Milan et al patent includes a handle and a plastic spiral section which is inserted into the endometrium and rotated to collect endometrial tissue. This device does not have a protective sleeve, as does the above Medoza Canula. It is believed that the device of the Milan et al patent has the same general shortcomings as the above-described Medoza Canula, and additionally has the shortcoming that wetting of the spiral section occurs during insertion, thereby substantially reducing the adherance of endometrial tissue to the spiral section. It is also believed that the spiral section does not dig sufficiently deeply into the endometrial walls to collect as wide a spectrum of possibly cancerous cells and tissues as is desirable.
Other methods of collecting endometrial cells and tissue include aspirator type devices (which operate to suck cells from the endometrial walls) and a type of device referred to as a "gravely jet washer". Both of these types of devices require expensive motor driven mechanisms. Such machines are not ordinarily available in a physicians office. In both types of devices, the collected cells are collected in a fluid, which must be strained through a filter in order to collect the cells so that they can be placed on a microscope slide by analysis. This type of procedure is not of a type which can be economically routinely performed in a typical physicians office.
It is an object of the invention to provide an inexpensive, efficient method of obtaining samples of endometrial cells and/or tissue.
It is another object of the invention to provide a method of obtaining endometrial tissue and cell samples which can be easily placed on a microscope slide for analysis.
It is another object of the invention to provide a method of obtaining endometrial tissue which is sufficiently uncontaminated to permit accurate diagnosis of endometrial cancer.
It is another object of the invention to provide an endometrial brush which may be inserted with minimum discomfort to the patient.
It is another object of the invention to provide an inexpensive endometrial brush which efficiently collects a broad spectrum of endometrial tissue and cell samples.
It is another object of the invention to provide an inexpensive endometrial brush which avoids wetting and/or contamination of its bristles during insertion and withdrawal of the endometrial brush.
It is another object of the invention to provide an endometrial brush to efficiently collect endometrial tissue and/or cell samples from the deepest portions of an endometrial cavity.
Briefly described, and in accordance with one embodiment thereof, the invention provides an endometrial brush and method for efficiently and inexpensively collecting samples of endometrial tissue and/or cells from the walls of a patient's endometrial cavity. The endometrial brush includes a handle, which may be permanently or detachably connected to a semi-rigid shaft. A flexible, slidable sleeve is provided on the shaft and can be slid forward along the shaft to cover the bristles of the brush during insertion and withdrawal and can be slid backward along the shaft to uncover the bristles in the endometrial cavity to permit scraping of sample tissue and cells therefrom. The semi-rigid shaft may be bent so that it conforms to the curvature of the passage through the vagina, cervix, and endometrial cavity of an individual patient. The shaft, when so bent, maintains its bent configuration so that when the endometrial brush is fully inserted, the bristles of the brush are suitably positioned for scraping and collecting sample tissue and cells from the endometrial walls. The bristles are helically wound to form a helix along a segment of the shaft furthest from the handle. A small, rounded bead is connected to the extreme end of the shaft beyond the bristles. The diameter of the bead is sufficiently small to permit insertion of the endometrial brush through the patient's cervix with minimum discomfort to the patient. The bead forms a seal with the inner surface of the flexible sleeve when the sleeve is slid forward to cover the bristles during insertion and withdrawal of the endometrial brush. In one embodiment of the invention, the rounded bead is omitted, and a group of end bristles fanning outwardly from the end of the shaft is provided to more efficiently scrape tissue and cell samples from the deepest portions of the endometrial cavity, where the probability of cancerous tissue and cells may be highest. According to the invention, the slidable sleeve is deployed to prevent the bristles from becoming "saturated" or wetted with moisture and tissue from the vaginal canal and cervical passage during insertion of the endometrial brush. After the bristles are uncovered in the endometrial cavity, the handle of the endometrial brush is then rotated and moved longitudinally to cause the bristles to "dig into" the endometrial walls to scrape a broad spectrum of cells and tissue therefrom. The sleeve is then deployed to cover the bristles, the endometrial brush is then withdrawn, and the sleeve is again retracted. The sample tissue and cells on the bristles are then wiped onto a microscope slide for immediate analysis. The endometrial brush may be discarded or sterilized for later use. In one embodiment of the invention, the handle is detachable from the shaft; the shaft and bristles thereof are disposable.